It's no surprise that mobile technology is an attractive opportunity for arts and cultural organisations. OFCOM suggest more than half the UK's mobile users have a smartphone – no other device offers access to such a wealth of information, exploration and connectivity while being inextricably entwined with our day to day lives.

In under four years there have been 25bn downloads from Apple's AppStore alone. Museum of London's revered Streetmuseum app is a fine example of the medium at its best. How hard can it be to make an app that entertains and educates?

In early 2011 Thought Den were commissioned to produce a playful mobile-based experience to take Tate's collection of artworks beyond the physical walls of the gallery. Their previous app, Tate Trumps, was hailed as a game-changer and demonstrated public appetite for mobile experiences. Magic Tate Ball was designed to appeal to more casual mobile users on an international scale. It is now Tate's most downloaded app, but after almost a year in production the journey was far from easy.

Credit must be given to Tate for writing an excellent brief. I believe the most successful digital projects are built on genuine collaboration between the content owners and the digital team. Tate clearly understand the value of their content and Thought Den were given ample freedom to harness the technical power of the medium and wrap it up in a compelling creative treatment. We pitched a few concepts and Magic Tate Ball stuck – it's a simple idea with a silly name, which is a winning combination.

When the app is downloaded, users are invited to give it a shake. By analysing the date, time of day, GPS location, local weather data and ambient noise levels, the clever search algorithm finds a piece of artwork from Tate's collection that is most relevant to the user's unique surroundings. The artwork is presented with a Twitter-sized tag that offers a fun or facty explanation of its relevance.

Jane Burton, Tate Media's head of content and creative director, says: "I love the serendipity of discovering art through Magic Tate Ball — you never know which artwork you're going to get. We aimed it at both existing Tate fans and new audiences who are interested in a more playful experience than cultural institutions typically offer."

The most fundamental lesson in app development for this audience is to keep it simple. People live busy lives and outside a dedicated gallery environment the barrier to engagement needs to be low – app developers and commissioners alike are far too easily distracted by the shiny possibilities of mobile technology.

Another secret to Magic Tate Ball's success was making sure the technology took a backseat. A complex process is required to collect the raw data from the user's surroundings and turn it into useful information. But all the user has to do is shake the phone; the magic happens in the background. Expert digital writer Hazel Grian, having worked on Kate Modern and the Star Trek ARG, was brought in to help write almost 2,500 artwork tags. These snippets of text played a huge role in helping each artwork resonate with that particular user in those particular surroundings. So content first, technology second.

After six months in production the app was submitted to the AppStore. Perhaps fearing the wrath of Mattel, owners of the original Magic 8 Ball brand, Apple rejected the app. Not wanting to be defeated we took it straight to Mattel's head office in the US where, to our delight, it was warmly received. A few months later their legal team sent through a signed letter of approval. This goes to show that taking a risk on the name, and persevering through to the end, really paid off for Tate.

A common mistake is to blow the whole budget on production and forget the essential role of marketing. However cool the idea, when competing against another few hundred thousand distractions, there is no guarantee it will reach your audience. We shot a 60 second viral video with Grama Film, hired seeding company Team Rubber and engaged in traditional PR activities.

A reskinned version of Magic Tate Ball for Nokia's OVI store launched two weeks before the iOS version, helping whet the appetite of Apple users. A week after launch Apple featured Magic Tate Ball in the AppStore's 'New and Noteworthy' section – download figures jumped to almost 4,000 per day which goes to show the importance of getting a publisher's blessing.

In only two months the app has achieved just short of 100,000 downloads, which is incredible for an art app. We collaborated closely with Tate, developed a simple idea, brought the stories to the fore and launched the idea with as much gusto as we could muster. Of course, we wouldn't have had quite that level success without a little sprinkling of magic along the way.